Remove Page.handleDialog method

This is a left-over after refactoring in f62cfc3b.

References #2.

docs/api.md

@@ -14,7 +14,6 @@
     - [page.extraHTTPHeaders()](#pageextrahttpheaders)
     - [page.setUserAgentOverride(userAgent)](#pagesetuseragentoverrideuseragent)
     - [page.userAgentOverride()](#pageuseragentoverride)
-    - [page.handleDialog(accept, promptText)](#pagehandledialogaccept-prompttext)
     - [page.url()](#pageurl)
     - [page.setContent(html)](#pagesetcontenthtml)
     - [page.navigate(url)](#pagenavigateurl)
@@ -107,12 +106,6 @@ Pages could be closed by `page.close()` method.
 
 - returns: [<string>](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type) Returns user agent override, if any.
 
-#### page.handleDialog(accept, promptText)
-
-- `accept` [<boolean>](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#Boolean_type) Wether accept or discard the dialog.
-- `promptText` [<string>](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type) Optional text to put inside the text prompt.
-- returns: [<Promise>](https://developer.mozilla.org/en/docs/Web/JavaScript/Reference/Global_Objects/Promise) Promise which resolves when the dialog is handled.
-
 #### page.url()
 
 - returns: [<Promise<string>>](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Data_structures#String_type) Promise which resolves with the current page url.

lib/Page.js

@@ -241,15 +241,6 @@ class Page extends EventEmitter {
         this.emit(Page.Events.Dialog, dialog);
     }
 
-    /**
-     * @param {boolean} accept
-     * @param {string} promptText
-     * @return {!Promise}
-     */
-    async handleDialog(accept, promptText) {
-        return this._client.send('Page.handleJavaScriptDialog', {accept, promptText});
-    }
-
     /**
      * @return {!Promise<string>}
      */